The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

One way of determining when you can plant oxalis is to look at the USDA zone info for Cambridge.

Planting Calendar for Oxalis

Frost tolerance for oxalis:	Not tolerant of frost.
When to plant:	After all chance of frost has passed.

It's probably not a good idea to plant oxalis until after the last frost when the weather gets warmer because they require warm weather.

The earliest that you can plant oxalis in Cambridge is May. However, you really should wait until June if you don't want to take any chances.

The last month that you can plant oxalis and expect a good harvest is probably August. Any later than that and your oxalis may not have a chance to fully mature. You can get started a couple of weeks earlier by starting your oxalis indoors.

Last Frost Date

The average date of last frost is May 15 in Cambridge. It might get as low as -30°F during the coldest months of winter.

Keep in mind that the actual date of last frost is not always accurate because it is based on the USDA zone info for Cambridge and it is different every year. Half of the time in Cambridge you get surprised by a frost after May 15 so always be ready to protect your oxalis in the event of a late frost.

USDA Zone Info for Cambridge

Here is the info for USDA Zone 4a.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-30°F
Highest Expected Low	-25°F

This means that on a really cold year, the coldest it will get is -30°F. On most years you should be prepared to experience lows near -25°F.

Plants to Grow in Cambridge

You may be interested in your other planting guides for Cambridge.